Let's assume Wade doesn't return. I'm on the fence. He's had some great games and fallen apart almost as many. In his defense, he had to deal with 3 of his starting 4 DB's being replaced and down to his 3rd ILB. We've scored more sacks to date than last year, but have notably less INT's.
Wade runs a 3-4 which uses 4-3 gap assignments. He's the only one in the league who does so. You won't find a plug-and-play reaplcement. Now with so many different fronts, 3-4 vs 4-3 is almost irrelevant these days, but you have to start somewhere. The philosophy of the 3-4 is for the front 3 to free up the OLB's to make plays. This really doesn't suit AD very much, but moreso than a conventional alignment 3-4.
So, if we replace Wade with another 3-4 guy re-signing Fowler is more important. Though we have some players in the wings. Brockers not as much. SJD probably takes his spot.
If we move to a 4-3, an alignment that favors AD, Brockers may be a more important keep. Fowler showed in Jax his not a hands-in-the-dirt DE. However, a 4-3 leaves us with a bunch of OLB types that don't quite fit at DE (OO, Ekuban) and no typical DE's. (Fox, maybe Lawler.) We'll have to commit a lot of resources to re-stocking the DL and that will affect our offseason plans.
Personally I'd move back to the 4-3. AD is a once in a generation player and everything we can do to unleash him while we still can is worth it to me. Using him in a not Wade Phillips 3-4 would be a waste of talent..